The Kirby Institute for Infection and Immunity in Society, The University of New South Wales, Sydney, Australia.
Vaccine. 2011 Aug 18;29(36):6086-91. doi: 10.1016/j.vaccine.2011.06.074. Epub 2011 Jul 1.
The RV144 trial conducted in Thailand was the first to demonstrate modest protective efficacy of an HIV vaccine. Its estimated initial efficacy was ∼74%, but this waned considerably over time.
We developed a mathematical model to reflect historical and current HIV trends across different at-risk populations in Thailand. The model was used to estimate the expected number of infections that would be averted if a vaccine with outcome characteristics similar to the RV144 vaccine was implemented in Thailand at varying levels of coverage.
In the absence of a vaccine, we projected roughly 65,000 new HIV infections among adults during the period between 2011 and 2021. Due to the waning efficacy of the vaccine, vaccination campaigns were found to have modest long-term public health benefit unless re-vaccination occurred. We forecast that an RV144-like vaccine with coverage of 30% of the population would lead to a 3% reduction in HIV incidence during the next 10 years. In comparison, 30% coverage of annual or biennial re-vaccination with the vaccine was found to result in 23% and 14% reductions in incidence, respectively. Coverage of 60% without re-vaccination resulted in a 7% reduction. Epidemiological outcomes were found to depend primarily on three factors: vaccination coverage, vaccine efficacy, and the duration of protection the vaccine provided.
Due to the short duration of protection the vaccine provides without re-vaccination, our model predicts modest benefit from a vaccination campaign with an RV144-like HIV vaccine in Thailand. Annual or biannual re-vaccination is predicted to greatly increase the long-term public health benefits of a vaccination campaign. The feasibility of vaccine implementation, as well as its economic viability, remains to be determined.
泰国开展的 RV144 试验首次证明了 HIV 疫苗具有一定的保护效果。其最初估计的疗效约为 74%，但随着时间的推移，疗效显著下降。
我们开发了一个数学模型，以反映泰国不同高危人群的历史和当前 HIV 趋势。该模型用于估计，如果在泰国实施一种具有类似于 RV144 疫苗结果特征的疫苗，在不同的覆盖水平下，预计可以避免多少感染。
在没有疫苗的情况下，我们预计在 2011 年至 2021 年期间，成年人中大约会新增 65000 例新的 HIV 感染。由于疫苗效力逐渐减弱，除非进行再次接种，否则疫苗接种活动的长期公共卫生效益有限。我们预测，在人群中覆盖率为 30%的类似于 RV144 的疫苗将在未来 10 年内导致 HIV 发病率降低 3%。相比之下，每年或每两年进行一次疫苗再接种的覆盖率为 30%，分别导致发病率降低 23%和 14%。如果不进行再接种，覆盖率为 60%则可导致发病率降低 7%。流行病学结果主要取决于三个因素：疫苗覆盖率、疫苗效力和疫苗提供的保护持续时间。
由于疫苗不进行再接种的保护持续时间短，我们的模型预测，在泰国开展类似于 RV144 的 HIV 疫苗接种活动的效益有限。每年或每两年进行一次疫苗再接种预计将大大增加疫苗接种活动的长期公共卫生效益。疫苗实施的可行性及其经济可行性仍有待确定。
